Microbiology for COMLEX Level 1 Practice Test

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• Paracoccidioides brasiliensis is best described as a dimorphic fungus with which budding pattern?
• Which flagellated protozoan causes giardiasis with fatty stools?
• Nocardia asteroides is best described as which combination of characteristics?
• Blood cultures in toxic shock syndrome due to Staphylococcus aureus are typically which?
• The most common cause of toxic shock syndrome is which organism?
• Which antibody is primarily involved in immediate hypersensitivity and anaphylaxis?
• The second most common cause of infectious mononucleosis is which pathogen?
• PAS staining is also seen in which liver condition due to diastase-resistant inclusions?
• In neonates (0-3 months), the most common cause of bacterial meningitis is which organism?
• Which mnemonic is used to remember the virulence factors of Corynebacterium diphtheriae?
• PPD induration thresholds: which is positive for recent immigrants, IVDU, healthcare workers, and prisoners?
• Parvovirus B19 infection mainly infects which type of cells?
• Which yeast commonly causes vulvovaginal candidiasis and thrush?
• Which HPV oncoproteins are associated with the oncogenic potential of human papillomavirus?
• Southern blot uses which type of hybridization to analyze DNA sequences?
• Endotoxin (LPS) is a major cause of septic shock in infections with which type of organisms?
• Which organism is most common cause of bacterial meningitis in elderly adults?
• Which protozoan parasite causes amoebic dysentery with liver abscesses?
• Which antibiotic class is ineffective against Mycoplasma due to lack of peptidoglycan cell wall?
• Which genus includes intracellular bacteria transmitted by arthropods and contains species causing RMSF and epidemic typhus?
• Which organism is a Gram-positive cocci in clusters that is catalase-positive and coagulase-positive, often causing skin infections?
• What is the primary mode of transmission for hantavirus pulmonary syndrome?
• In the H. pylori treatment regimen, which agent acts as a proton pump inhibitor or H2 blocker?
• Hand-foot-mouth disease is caused by which virus?
• Sporothrix schenckii classically shows which microscopic morphology?
• Which intestinal nematode causes intestinal obstruction and is transmitted via the fecal-oral route, often in children?
• Which exotoxin is most associated with necrotizing fasciitis due to Streptococcus pyogenes?
• The organism Malassezia furfur is best described as which?
• Chlamydia psittaci is characterized as which type of organism and is associated with exposure to which animals?
• Which organism is best visualized in CSF using India ink staining and is a common cause of meningitis in AIDS patients?
• Interferon-y Release Assay (IGRA) is used to detect what?
• Western blot is used as a confirmatory test for HIV by detecting which of the following?
• Which virus is a DNA virus associated with cervical cancer and genital warts via E6/E7 oncoproteins?
• Kinesin is best described as?
• Which bacterium is most closely associated with dental caries and is part of the viridans group?
• Human immunodeficiency virus (HIV) is best described as which type of virus?
• Scarlet fever is caused by which organism?
• Which Gram-negative diplococcus is associated with urethritis and conjunctivitis and does not ferment maltose?
• In intravenous drug users, rapid onset endocarditis most commonly affects which heart valve?
• Which condition presents with redness and swelling of the skin with well-demarcated borders?
• Inhalational anthrax typically presents with which radiographic finding?
• Which cell wall component is unique to Gram-positive bacteria?
• S. aureus pneumonia is a frequent cause in which patient group?
• Rheumatic fever is diagnosed using which criteria?
• Pneumocystis jirovecii pneumonia is an opportunistic infection common in AIDS patients; which organism is responsible?
• Which genetic element mediates the spread of antibiotic resistance among bacteria?
• Erythema infectiosum (Fifth disease) is associated with which of the following findings?
• Which organism is classically associated with exposure to sheep or goats and has a poly-D-glutamate capsule?
• Which virus family includes influenza viruses and has a segmented genome prone to antigenic shift and drift?
• Which organism is a Gram-positive, lancet-shaped diplococcus with a polysaccharide capsule and is a leading cause of community-acquired pneumonia?
• Which virulence factor of Streptococcus pyogenes is most associated with rheumatic fever following pharyngitis?
• Q fever is caused by which organism?
• Which Gram-negative diplococcus ferments both glucose and maltose and is a common cause of meningitis?
• Erythema infectiosum (Fifth disease) is caused by which virus?
• What is the most important virulence factor for Streptococcus pyogenes?
• In bacterial diagnostics, which test differentiates Staphylococcus aureus from Staphylococcus epidermidis by coagulase activity?
• Which obligate intracellular bacterium causes Q fever?
• Northern blot is used to study gene expression by detecting which biomolecule?
• The presynaptic blockade of acetylcholine release at the neuromuscular junction is caused by which toxin?
• Patients with a central venous catheter receiving total parenteral nutrition are at risk for infection with which organism?
• Congenital syphilis is caused by which organism?
• Scarlet fever is best described as which statement?
• Which antibody is the most abundant in serum and can cross the placenta?
• Which bacterium produces a toxin that inactivates elongation factor-2 and causes diphtheria?
• Northern blot is used to detect which type of nucleic acid?
• Which encapsulated organism is a leading cause of community-acquired pneumonia?
• Which family of viruses has segmented negative-sense RNA and includes influenza; prone to antigenic shift and drift?
• Which infection is prevented by vaccination and is typically seen in unvaccinated individuals?
• Diphtheria toxin inactivates which host factor to inhibit protein synthesis?
• Sporothrix schenckii is best described as which type of organism?
• Which staining feature is characteristic of Corynebacterium diphtheriae?
• Which histopathologic finding is characteristic of Coccidioides immitis?
• Clostridium perfringens gas gangrene is often associated with which context?
• Which virus is the most common cause of croup in children?
• Which organism is classically associated with aerosolized water from air conditioning and water systems and causes Legionnaires' disease?
• Sporothrix schenckii infection route is most commonly via what exposure?
• Which staining method is commonly used to visualize Chlamydia trachomatis in clinical specimens?
• Which manifestation is part of the Jones criteria for acute rheumatic fever?
• What is the initial management for suspected meningitis in children?
• Rocky Mountain Spotted Fever is caused by which organism?
• Which parasite infection is classically associated with iron-deficiency anemia due to blood loss in the intestinal mucosa?
• Which feature is unique to Gram-negative bacteria?
• Which encapsulated Gram-negative rod is a common cause of pneumonia in alcoholics and produces a thick, mucoid capsule with currant jelly sputum?
• In individuals older than 10 years, the most common cause of bacterial meningitis is which organism?
• Which flagellated protozoan causes giardiasis with fatty, foul-smelling stools?
• Which yeast commonly causes vulvovaginal candidiasis and thrush?
• Which virulence factor of Staphylococcus aureus binds the Fc region of IgG, inhibiting opsonization?
• Which organism is most commonly responsible for endocarditis after dental trauma or caries?
• Which helminth is transmitted via skin penetration by larvae and can cause iron-deficiency anemia?
• Candida species commonly shows which morphological form on microscopy?
• Which motor protein facilitates anterograde transport of herpes simplex virus during reactivation to skin and mucosa?
• Patients with a deficiency of terminal complement components (C5-C9) are at increased risk for infections with which bacteria?
• Which complement deficiency predisposes to disseminated Neisseria infections?
• A wound infection with gas production and crepitus is most likely caused by which organism?
• Which vaccine type uses killed or inactivated pathogens and generally requires booster doses?
• In sickle cell disease, which two infections are most commonly seen?
• The virulence factor of Streptococcus pyogenes linked to rheumatic fever is:
• Which obligate intracellular bacterium causes Rocky Mountain spotted fever?
• Praziquantel is the treatment for infections caused by which parasite group?
• Which blot is used to detect DNA?
• LPS endotoxin is found in which part of Gram-negative bacteria?
• Which protozoan parasite has a ring form inside red blood cells and causes malaria?
• Herpes zoster presents with which combination of features?
• Which yeast-like organism commonly causes meningitis in AIDS patients and is detected by India ink staining?
• Primary TB is commonly characterized by which feature?
• Which organism is Gram-positive, spore-forming anaerobe that causes gas gangrene?
• Which toxin blocks acetylcholine release at the neuromuscular junction, causing flaccid paralysis?
• Rheumatic fever commonly damages which heart valve due to molecular mimicry with Streptococcus pyogenes M protein?
• Which curved Gram-negative rod is associated with infections from undercooked poultry and can cause Guillain-Barré syndrome?
• Clostridium perfringens infection is classically associated with which finding?
• Koplik spots are characteristic of which disease?
• In adults with rubella infection, what is a common complication?
• Roseola is caused by which herpesvirus?
• Which herpesvirus causes chickenpox and shingles and remains latent in dorsal root ganglia?
• Which feature of Chlamydia trachomatis explains why penicillin antibiotics are not effective?
• Pott disease is a form of vertebral osteomyelitis caused by which organism?
• Which staining approach is listed as a method to visualize Chlamydia trachomatis in clinical specimens?
• Which spirochete causes syphilis and is diagnosed using dark-field microscopy or VDRL?
• HIV gp41 is which type of protein?
• Gardnerella vaginalis is best described as which type of organism that causes bacterial vaginosis and is associated with a fishy odor?
• Which protozoan parasite has a ring form inside red blood cells and causes malaria?
• Epstein-Barr virus is a member of which virus family?
• Which herpesvirus is associated with mononucleosis and is linked to Burkitt lymphoma and nasopharyngeal carcinoma?
• Which molecule in the cell wall of Mycobacterium tuberculosis contributes to acid-fast staining and environmental resistance?
• Which T-cell subset is implicated in the pathogenesis of rheumatic fever?
• Necrotizing fasciitis due to Streptococcus pyogenes is most notably associated with which clinical finding?
• Which microscopy pattern is characteristic of Paracoccidioides brasiliensis?
• Adaptive immune mechanism for reinfection w/ influenza virus: which is correct?
• What is a common treatment for CA-MRSA skin infections?
• Which feature is unique to Gram-positive bacteria?
• Which symptom is most indicative of vertebral osteomyelitis?
• Which acid-fast rod causes leprosy and is treated with dapsone and rifampin?
• For invasive Staphylococcus aureus infections due to MSSA, which penicillinase-resistant antibiotic is preferred?
• Which subunit of the ribosome is targeted by drugs used to treat tuberculosis?
• What component of the Mycobacterium tuberculosis cell wall contributes to resistance to desiccation and acid-fast staining?
• Which description best fits chickenpox?
• Paracoccidioides brasiliensis is most commonly found in which geographic region?
• M protein of Streptococcus pyogenes primarily functions to:
• What is a known reservoir for Paracoccidioides brasiliensis?
• Treatment for toxoplasmosis in immunocompromised patients is?
• Which feature is part of the classic presentation of Streptococcus pyogenes pharyngitis?
• Clue cells on a vaginal smear are most commonly associated with infection by which organism?
• In infants less than 2 years old with RSV bronchiolitis, the mainstay of treatment is:
• Hepatitis C virus genetic instability is due to which feature?
• Which Shiga-like toxin-producing E. coli strain causes hemorrhagic colitis and HUS?
• How does Mycobacterium tuberculosis confer resistance to antibiotics?
• A thick, golden crust over a pustular lesion is most characteristic of which infection?
• What mechanism allows Neisseria gonorrhoeae to vary its surface antigens?
• Empiric therapy for suspected bacterial meningitis typically includes which combination?
• After a positive HIV ELISA, which test is used as a confirmatory test?
• A major determinant of viral tropism and host range is which viral component?
• Toxoplasmosis in immunocompromised patients shows which brain imaging finding?
• Malaria infection presents with cyclical fever and intravascular hemolysis due to rupture of infected red blood cells. Which genus is responsible?
• Which organism lacks a cell wall and frequently causes walking pneumonia in young adults, best treated with macrolides?
• What is the correct order of the three stages of Bordetella pertussis infection?
• The green discoloration of pus or sputum in bacterial infections is due to which enzyme?
• Hot tub folliculitis is most commonly caused by which organism?
• Which Staphylococcus species is typically coagulase-positive?
• In the described regimen for Helicobacter pylori infection, which drug is a macrolide?
• In an HIV-positive patient with multiple ring-enhancing brain lesions and no exposure to cats, which diagnosis is most likely?
• Rocky Mountain Spotted Fever is commonly transmitted by which tick species?
• Scarlet fever is caused by infection with Streptococcus pyogenes that produces which toxin?
• Which test is used as the initial screening test for HIV infection?
• Which bacterium binds Fc portion of IgG via Protein A to evade opsonization?
• Sporothrix schenkii is best described by which morphological feature?
• Which of the following is a distinguishing feature of Gram-negative bacteria compared with Gram-positive bacteria?
• Which helminth causes perianal itching in children and is typically treated with albendazole or mebendazole?
• Which strain of Escherichia coli is associated with hemorrhagic colitis and hemolytic-uremic syndrome due to Shiga-like toxin?
• Pityriasis versicolor has which characteristic microscopic appearance?
• Which organism is a spirochete transmitted by ticks and associated with erythema migrans?
• Roseola presents with which sequence of clinical findings?
• Antigenic variation in Neisseria gonorrhoeae explains which phenomenon?
• In a transplant patient with pneumonia, which pathogen is most likely?
• Antibiotic-associated diarrhea with pseudomembranous colitis is most commonly caused by which organism and its toxins A and B?
• Which retrovirus integrates into the host genome and leads to acquired immunodeficiency syndrome?
• Periodic acid-Schiff staining is classically positive in which disease?
• Which mold causes aspergillosis with acute-angle branching hyphae?
• Which protozoan parasite causes amoebic dysentery with liver abscesses?
• Malaria is caused by Plasmodium species and is transmitted by which mosquito?
• Which Gram-negative rod is commonly associated with hot-tub folliculitis and cystic fibrosis; thrives in moist environments?
• Secondary (reactivation) TB is typically associated with which imaging finding?
• In an AIDS patient with meningitis, which organism is most likely?
• Rubeola, also known as measles, is caused by which virus?
• Hantavirus pulmonary syndrome is classically associated with exposure in which region and via which route?
• Paracoccidioides brasiliensis is the organism responsible for Paracoccidioidomycosis; which organism is correct?
• Which acid-fast organism is responsible for tuberculosis and is identified by Ziehl-Neelsen staining?
• In patients who suffer from chronic itching disorders, breaks in the skin may be infected by which pathogen?
• Ether exposure inactivates which class of viruses?
• Kaposi sarcoma is associated with infection by which virus?
• Pseudomonas aeruginosa is most commonly seen in which settings?
• Which Salmonella serotype is classically associated with typhoid fever?
• Albendazole or mebendazole is used to treat infections with which parasite?
• Pityriasis versicolor presents with what skin findings?
• Vertebral tuberculosis (Pott disease) histology typically shows which of the following?
• Peptidoglycan synthesis is inhibited by which class of antibiotics?
• Which trematode causes schistosomiasis and is treated with praziquantel?
• Lyme disease is transmitted by which tick species?
• Which protozoan parasite causes vaginal itching and discharge with a strawberry cervix?
• Which component is a key virulence factor of Gram-negative rods?
• Infection with Streptococcus bovis is most strongly associated with which condition?
• Which tick species is classically associated with Colorado tick fever?
• Which virulence factor binds the Fc portion of IgG to prevent opsonization?
• The major virulence factor of Clostridium tetani is which toxin?
• Which organism is a Gram-negative rod commonly associated with nosocomial infections and burns wound infections and has a distinctive fruity odor?
• In hospital settings, intravascular catheters predispose to bacteremia and sepsis with which organism?
• Which Gram-negative diplococcus ferments maltose?
• Scabies is primarily transmitted by which route?
• A young adult with mild, persistent fever and dry cough has a chest radiograph showing patchy bilateral interstitial infiltrates but a negative Gram stain; which organism is most likely?
• Erythema infectiosum, caused by parvovirus B19, can cause which complication in pregnancy?
• Poliomyelitis causes degeneration of which neurons in the spinal cord?
• Histoplasma capsulatum is a dimorphic fungus most commonly associated with histoplasmosis in which geographic region?
• Cryptococcus neoformans has which distinctive feature?
• Which statement correctly describes a key feature of LPS endotoxin in Gram-negative bacteria?
• Paracoccidioidomycosis is classically described by which morphological form?
• Which supplement should be given with isoniazid to prevent peripheral neuropathy?
• During central venous catheter insertion, which action should be taken when the catheter is no longer needed?
• In children aged 3 months to 10 years, which organism is the most common cause of bacterial meningitis?
• Malassezia furfur is the etiologic agent of which condition?
• In an AIDS patient with meningitis, which organism is most likely to be the cause?
• Rubella is caused by which virus?
• Paracoccidioides brasiliensis infection is associated with exposure to which animals?
• A child with acute otitis media is most commonly infected by which encapsulated Gram-positive diplococcus?
• Erysipelas is most commonly caused by infection with which organism?
• IGRA tests measure the activity of which cells in response to TB antigens?
• Which feature is typically absent in CMV mononucleosis compared with EBV mononucleosis?
• Which organism causes epidemic typhus and is transmitted by lice?
• Which feature is most characteristic of rubella?
• Southwestern blot is used to detect which type of molecules?
• A patient presents with a fever and a maculopapular rash that begins on the face and spreads to the trunk, with cervical lymphadenopathy. This presentation is most consistent with which infection, particularly if vaccination status is uncertain?
• Which spirochete is transmitted by ticks and causes erythema migrans?
• Which statement about protective immunity to influenza reinfection is true?
• Congenital rubella syndrome commonly includes which triad of defects?
• RSV bronchiolitis is most common in children under what age?
• Penicillins and other beta-lactam antibiotics disrupt bacteria by which mechanism?
• Which LPS substructure is primarily responsible for triggering the host immune response by activating macrophages?
• Mycoplasma cell wall characteristic is?
• Which rash pattern is associated with erythema infectiosum?
• Which CSF profile is most typical of bacterial meningitis?
• Which disease is classically associated with strawberry tongue and a sandpaper-like rash?
• Which setting is commonly associated with community-acquired MRSA infections?